Gentoo: MIT Kerberos 5 Multiple vulnerabilities
Posted by Benjamin D. Thomas   
Gentoo MIT Kerberos 5 is vulnerable to a Denial of Service attack and remote execution of arbitrary code, possibly leading to the compromise of the entire Kerberos realm.
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Gentoo Linux Security Advisory                           GLSA 200507-11
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                                            http://security.gentoo.org/
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  Severity: High
     Title: MIT Kerberos 5: Multiple vulnerabilities
      Date: July 12, 2005
      Bugs: #98799
        ID: 200507-11

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Synopsis
========

MIT Kerberos 5 is vulnerable to a Denial of Service attack and remote
execution of arbitrary code, possibly leading to the compromise of the
entire Kerberos realm.

Background
==========

MIT Kerberos 5 is the free implementation of the Kerberos network
authentication protocol by the Massachusetts Institute of Technology.

Affected packages
=================

    -------------------------------------------------------------------
     Package             /  Vulnerable  /                   Unaffected
    -------------------------------------------------------------------
  1  app-crypt/mit-krb5     < 1.4.1-r1                     >= 1.4.1-r1

Description
===========

Daniel Wachdorf discovered that MIT Kerberos 5 could corrupt the heap
by freeing unallocated memory when receiving a special TCP request
(CAN-2005-1174). He also discovered that the same request could lead to
a single-byte heap overflow (CAN-2005-1175). Magnus Hagander discovered
that krb5_recvauth() function of MIT Kerberos 5 might try to
double-free memory (CAN-2005-1689).

Impact
======

Although exploitation is considered difficult, a remote attacker could
exploit the single-byte heap overflow and the double-free vulnerability
to execute arbitrary code, which could lead to the compromise of the
whole Kerberos realm. A remote attacker could also use the heap
corruption to cause a Denial of Service.

Workaround
==========

There are no known workarounds at this time.

Resolution
==========

All MIT Kerberos 5 users should upgrade to the latest available
version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=app-crypt/mit-krb5-1.4.1-r1"

References
==========

  [ 1 ] CAN-2005-1174
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-1174
  [ 2 ] CAN-2005-1175
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-1175
  [ 3 ] CAN-2005-1689
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-1689
  [ 4 ] MITKRB5-SA-2005-002
        http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2005-002-kdc.txt
  [ 5 ] MITKRB5-SA-2005-003
        http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2005-003-recvauth.txt

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

  http://security.gentoo.org/glsa/glsa-200507-11.xml

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
=======

Copyright 2005 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/2.0